I think they don't catch everything that people try to slip by filters etc. Maybe it depends who sees your images etc. Like this pirate game i played allowed clan logos in game. I uploaded a person covered in some blood for a pirate crew logo and i get banned. Another person uploaded hardly dressed person with blood on the face looking crazy and it was his groups picture where everyone can see it.
Ok, after seeing that one picture example from an answer i guess they are getting lazy? That's worst than any image i seen 2 years ago.